Puerto Rico’s environment agency is trying to better protect a bioluminescent bay that’s considered one of the brightest in the world.

Mosquito Bay attracts thousands of visitors with its bright waters filled with microscopic organisms that light up when disturbed. It’s located on Vieques, an island popular with tourists just east of the main island of Puerto Rico.

Environment Secretary Carmen Guerrero Perez said Sunday that access to the bay needs to be improved to prevent sediment from getting in the waters. She said officials are evaluating designs for an upgraded road to the bay. Puerto Rico is also looking at ways to combat light pollution.

Guerrero said one of the biggest challenges will be figuring out how many visitors to allow. Now, there are no limits on how many people can visit the bay.